FIG. 3 shows a general chip construction of a semiconductor device including an ultraviolet ray erasable type semiconductor memory device.
In FIG. 3, the reference numeral 1 designates a semiconductor chip, the reference numeral 2a designates wire bonding electrodes provided on the semiconductor chip 1. The reference numeral 2b designates electrode windows, and the reference numeral 3 designates a protection film deposited on the surface of the semiconductor chip 1. This protection film 3 is a silicon nitride film, silicon dioxide film, or both. The reference numeral 4 designates a metal wire for connecting the wire bonding electrode 2a and a package terminal. The reference numeral 5 designates a transparent window of the package provided above the semiconductor chip 1. The reference numeral 6 designates a hollow section in which inactive gas is sealed.
In an integrated circuit element provided with such an ultraviolet ray erasable erasion type memory device, the upper layer protection film 3 and the transparent window 5 comprise material which is transparent to ultraviolet rays. Accordingly, with this device a reading out operation is conducted by providing a cover (not shown) above the transparent window 5 to cut off the ultraviolet rays, and a memory erasing operation is conducted by irradiating ultraviolet rays on to the device from an outside source with the cover removed.
The above-described integrated circuit element has an ultraviolet ray erasable type element construction by which erasing and writing can be conducted at desired times repeatedly, and an element oriented to conduct only the writing function with no erasing function can be also combined together with the above-described element on the same chip. This writing function oriented element is designed to be used with a chip which includes an ultraviolet ray erosion type memory device and is constructed such that a writing operation can be conducted only one time and the memory content can not be erased thereafter. An element having this construction is called an "OTP" (One Time Programmable semiconductor element). FIG. 4 shows a brief construction of such an element, wherein the reference numeral 7 designates molding material. This semiconductor element is constructed by using a cheaper molding package than that having a transparent window as shown in FIG. 3. This device does not have a hollow section such as 6 of the device of FIG. 3, and the molding material and the semiconductor chip are disposed so as to be in contact with each other.
The prior art OTP is constructed in such a manner, and has an advantage of low cost. However, since the package molding material and the semiconductor chip are provided in contact with each other in this prior art OTP, the OTP is likely to include defects after construction due to the pressure of the molding material, the local stresses applied to the semiconductor chip by the fillers, and the difference in the thermal expansion properties between the upper layer protection film of the semiconductor chip and the molding material. Furthermore, it is difficult or impossible to conduct tests and remove faulty devices after construction.